Oral tobacco material

ABSTRACT

An oral tobacco material includes a powdered tobacco, and a basic salt of carbonic acid and an acidic salt of phosphoric acid as a pH adjusting agent. The basic salt of carbonic acid and the acidic salt of phosphoric acid are included in a total amount of 6% by weight or more of the dry weight of the powdered tobacco and are incorporated such that the initial pH of the oral tobacco material becomes from 7 to 8.5, and the oral tobacco material has a water content of 15% by weight or more.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation application of PCT Application No.PCT/JP2011/057656, filed Mar. 28, 2011 and based upon and claiming thebenefit of priority from Japanese Patent Application No. 2010-075876,filed Mar. 29, 2010, the entire contents of all of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an oral tobacco material, specificallyto an oral tobacco material that is excellent in pH stability when it isstored at room temperature.

2. Description of the Related Art

Oral tobacco products such as moist-snuff or SNUS have attractedattention in recent years. These oral tobacco products comprise an oraltobacco material comprising a wet powdered tobacco, accommodated in amoisture permeable pouch, and one can enjoy the taste and flavor of thepowdered tobacco by inserting the product between the lip and gum in theoral cavity.

Such wet powder tobacco itself is weakly acid in general (pH: about 4.0to 6.0), and thus bacteria grow easily. Therefore, in order to increasestorage stability by inhibiting the growth of bacteria, a pH adjustingagent is added to the powdered tobacco so as to adjust the pH thereof toa pH of approximately neutral to alkaline. Furthermore, in order toimpart desirable flavor, the pH is adjusted to one desired pH withinapproximately neutral to alkaline regions. In addition, it is desiredthat the adjusted pH is substantially maintained over a whole storageperiod in view of maintenance of the quality of products.

Patent Document 1 discloses that an alkali metal hydroxide, a metalcarbonate and a metal bicarbonate are used as a pH adjusting agent or abuffering agent. However, all of these pH adjusting agents and bufferingagents are alkaline. Patent Document 1 also discloses that an inorganicfiller is incorporated in a powdered tobacco, and describes calciumphosphate as an example of the inorganic filler, but calcium phosphateis alkaline.

Patent Document 2 discloses a tobacco product comprising magnesiumcarbonate as a pH adjusting agent for rendering the tobacco materialalkaline. However, magnesium carbonate is alkaline. Furthermore, PatentDocument 2 discloses that an additional pH adjusting agent may be usedin addition to magnesium carbonate, and describes sodium carbonate,phosphates and the like as examples of the pH additional adjustingagent. However, this additional pH adjusting agent is used to rapidlybring the tobacco material to a desired pH value (neutral or alkaline),and thus it can be considered that the phosphates as described arealkaline.

The amount of an alkaline substance that is required to bring the wetpowdered tobacco to a desired neutral or alkaline pH value is determinedwithout variation. In addition, since the amount of the alkalinesubstance used to bring the powdered tobacco to a desired pH value isrelatively small, the adjusted pH value cannot be maintained over a longterm. Therefore, an oral tobacco material comprising a powdered tobaccowhose initial pH has been adjusted by using only an alkaline substancemust be stored at a low temperature (from −20° C. to 10° C.) rather thanroom temperature.

In addition, when a large amount of alkaline substance is added to anoral tobacco material so as to maintain storage stability over a longterm, the pH value is increased significantly, and the mucosa may beinjured when the oral tobacco material is inserted into the oral cavity.It is desirable that an oral tobacco material comprising a wet powderedtobacco to be inserted into the oral cavity has a pH of 8.5 or less.

CITATION LIST Patent Documents

-   Patent Document 1: Jpn. PCT National Publication No. 2009-508523-   Patent Document 2: International Publication No. WO2009/082331

BRIEF SUMMARY OF THE INVENTION Problem to be Solved

An object of the present invention is to provide an oral tobaccomaterial that shows excellent storage stability over a long term at roomtemperature.

Solution to Problem

The present invention provides an oral tobacco material comprising apowdered tobacco, and a basic salt of carbonic acid and an acidic saltof phosphoric acid as a pH adjusting agent, wherein the basic salt ofcarbonic acid and the acidic salt of phosphoric acid are contained in atotal amount of 6% by weight or more of a dry weight of the powderedtobacco and are incorporated such that an initial pH of the oral tobaccomaterial becomes from 7 to 8.5, and the oral tobacco material has awater content of 15% by weight or more.

Effects of Invention

The oral tobacco material of the present invention comprises arelatively large amount of pH adjusting agent, and thus shows excellentstorage stability over a long term at room temperature.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 is a graph showing the change in pH over time when the oraltobacco materials of Examples 1 and 2 and Comparative Example 1mentioned below were stored in an atmosphere at a temperature of 25° C.and a relative humidity of 60%;

FIG. 2 is a graph showing the change in pH over time when the oraltobacco materials of Examples 1 and 2 and Comparative Example 1mentioned below were stored in an atmosphere at a temperature of 35° C.and a relative humidity of 60%;

FIG. 3 is a graph showing the change in pH over time when the oraltobacco materials of Example 3 and Comparative Example 2 mentioned belowwere stored in an atmosphere at a temperature of 25° C. and a relativehumidity of 60%; and

FIG. 4 is a graph showing the change in pH over time when the oraltobacco materials of Example 4 and Comparative Example 3 mentioned belowwere stored in an atmosphere at a temperature of 25° C. and a relativehumidity of 60%.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter the various embodiments of the present invention will beexplained in detail.

The oral tobacco material of the present invention comprises a powderedtobacco, and a basic salt of carbonic acid and an acidic salt ofphosphoric acid as pH adjusting agent. The basic salt of carbonic acidand the acidic salt of phosphoric acid are contained in a total amountof 6% by weight of the dry weight of the powdered tobacco and areincorporated such that the initial pH of the oral tobacco materialbecomes from 7 to 8.5. The oral tobacco material has a water content of15% by weight or more. The initial pH represents the pH as adjusted bythe pH adjusting agent.

The powdered tobacco contained in the above-mentioned oral tobaccomaterial includes a powder of lamina of tobacco, a mixture of powders oflamina and midrib of tobacco, a powder of reconstituted tobacco, and amixture of a powder of reconstituted tobacco and a powder of lamina oftobacco. Examples of the varieties of tobacco may include burleytobacco, flue-cured tobacco, oriental tobacco, dark-cured tobacco andRustica tobacco.

The pH adjusting agent contained in the oral tobacco material iscomposed of a combination of a basic salt of carbonic acid and an acidicsalt of phosphoric acid. The basic salt of carbonic acid is preferablyselected from the group consisting of sodium carbonate and potassiumcarbonate. A mixture of these basic salts of carbonic acid can also beused. The acidic salt of phosphoric acid is preferably selected from thegroup consisting of sodium dihydrogen phosphate and potassium dihydrogenphosphate. A mixture of these acidic salts of phosphoric acid can alsobe used.

The basic salt of carbonic acid and the acidic salt of phosphoric acidare contained such that the initial pH of the oral tobacco materialbecomes from 7 to 8.5, and in a total amount of 6% by weight or more ofthe dry weight of the powdered tobacco. When the pH value is less than7, it is difficult to inhibit the growth of bacteria, whereas when thepH value exceeds 8.5, the mucosa in the oral cavity may be injured.Furthermore, when the total amount of the basic salt of carbonic acidand the acidic salt of phosphoric acid is less than 6% by weight, longterm storability at room temperature (from 15° C. to 35° C.) may bedeteriorated. As already mentioned, the powdered tobacco shows a pHvalue of from about 4.0 to 6.0. Furthermore, since the pH value of theoral tobacco material is adjusted to from 7 to 8.5 by using both anacidic substance (the acidic salt of phosphoric acid) and a basicsubstance (the basic salt of carbonic acid) in the present invention,even the basic substance (the basic salt of carbonic acid) is added insuch a large amount that the pH of the oral tobacco material goes farbeyond 8.5, the pH can be adjusted to from 7 to 8.5 by the acidicsubstance. Therefore, in the case where the pH of an oral tobaccomaterial is adjusted to one desired value by using an alkaline substancealone, the amount of the alkaline substance is determined withoutvariation, whereas in the present invention, the use amounts of theacidic substance (the acidic salt of phosphoric acid) and basicsubstance (basic salt of carbonic acid) can be changed significantly inadjusting the pH value of the oral tobacco material to one desired pHvalue. It is preferable that the acidic salt of phosphoric acid is usedin an amount of 1% by weight or more of the dry weight of the powderedtobacco. The acidic salt of phosphoric acid is generally used in anamount of 10% by weight or less of the dry weight of the powderedtobacco. The use amount of the basic salt of carbonic acid with respectto the use amount of the acidic salt of phosphoric acid is determined bythe initial pH value of the oral tobacco material of from 7 to 8.5.

In the present invention, the oral tobacco material has a water contentof 15% by weight or more. The pH adjusting agent used in the presentinvention can exert the desired effect in the oral tobacco materialhaving a water content of 15% by weight or more. Oral tobacco materialsgenerally have a water content of 50% by weight or less.

The oral tobacco material of the present invention may compriseadditives such as flavoring agent, a wetting agent and the like.

Examples of the flavoring agent may include menthol, mint, amino acids(glycine etc.), vegetable extracts (eucalyptus, rosemary, GSE),flavonoids, Vitamin E, Vitamin C, citric acid, sodium chloride,monosaccharides such as fructose, disaccharides such as sucrose,oligosaccharides, other polysaccharides, cinnamon, horseradish (Japanesehorseradish), spice-based spices such as red pepper, Japanese pepper,clove, ginger, turmeric, allspice and cardamom, herb-based spices suchas basil, bay leaves, mabyora, oregano, rosemary, sage, tarragon, thyme,sesame, garlic and onion, seed-based spices such as caraway, anise leed,celery seed, coriander, cumin seed, dill seed, funnel, mace, nutmeg andpoppy seed, chocolate, citrus fruits and other fruits flavors, vanillin,ethyl vanillin, bergamot oil, linalool, lemon oil and the like. Theflavoring agent can be used in an amount of from 1% by weight to 5% byweight of the dry weight of the powdered tobacco.

The wetting agent may include polyhydric alcohols such as glycerin andpropylene glycol, sugar alcohols such as erythritol, xylitol andsorbitol, hyaluronic acid, and the like. The wetting agent can be usedin an amount of from 1% by weight to 5% by weight of the dry weight ofthe powdered tobacco.

In order to prepare the oral tobacco material of the present invention,at first, the water content of the powdered tobacco itself as a rawmaterial is measured. The water content can be measured by using acommercially available heating and drying type moisture analyzer (forexample, MX-50 manufactured by A&D Company, Limited). Next, the amountof water required for adjusting the water content of the oral tobaccomaterial to 15% by weight or more is calculated. The required wateramount Z can be calculated by the formula:Z={X(1−a/100)+Y}/(1−b/100)−(X+Y). In the formula, X is the weight of theraw material powdered tobacco, a is the water content of the rawmaterial powdered tobacco (%), Y is the total weight of the additivesubstances such as the pH adjusting agent and the wetting agent, and bis the aimed water content of the oral tobacco material (%).Predetermined amounts of basic salt of carbonic acid and acidic salt ofphosphoric acid, and where necessary, a water-soluble additive are addedto the thus-calculated amount of water to give an aqueous solution, andthe whole amount of the obtained aqueous solution can be added to thepowdered tobacco of the weight X. Other additives can be incorporatedinto the obtained wet powdered tobacco. The oral tobacco material of thepresent invention is generally free from magnesium carbonate.

The oral tobacco material of the present invention is accommodated in awater-permeable pouch known per se to provide an oral tobacco product.

The oral tobacco material of the present invention can substantiallymaintain the initial pH that has been adjusted by the pH adjusting agentof the present invention for at least 6 months even at room temperature(from 15° C. to 35° C.), and thus is excellent in storage stability atroom temperature.

EXAMPLES

Hereinafter the present invention will be explained by Examples, but thepresent invention is not construed to be limited by those Examples.

Examples 1 and 2 and Comparative Example 1

A raw material powdered tobacco was prepared by blending, as rawmaterials, powders of Rustica, dark-cured tobacco and tobacco mid-rib inamounts of 25% by weight, 25% by weight and 50% by weight, respectively,and the water content thereof was measured by the following technique.

The water content of 5.0 g of the raw material powdered tobacco wasmeasured at 80° C. by using a heating and drying type moisture analyzer(MX-50 manufactured by A&D Company, limited). As the result thereof, thewater content was 14.0% by weight. From the water content of this rawmaterial powdered tobacco, the amount of water required for adjustingthe final water content of the oral tobacco material to approximately25% by weight was calculated, and the calculated amount of water wasprepared.

In Example 1, sodium carbonate, sodium dihydrogen phosphate and glycerinin amounts corresponding to 4.8% by weight of sodium carbonate, 1.9% byweight of sodium dihydrogen phosphate and 5.0% by weight of glycerin onthe basis of the dry weight of the raw material powdered tobacco,respectively, were added to the prepared water, and the whole amount ofthe obtained aqueous solution was sprayed on the raw material powderedtobacco. The thus-obtained oral tobacco material had a final watercontent of 25.44% by weight and had an initial pH measured by the pHmeasurement method mentioned below of 8.09.

In Example 2, an oral tobacco material was prepared in the same manneras in Example 1, except that sodium carbonate, sodium dihydrogenphosphate and glycerin in amounts corresponding to 8.0% by weight ofsodium carbonate, 4.1% by weight of sodium dihydrogen phosphate and 5.0%by weight of glycerin on the basis of the dry weight of the powderedtobacco were added to the prepared water. The obtained oral tobaccomaterial had a final water content of 26.39% by weight and had aninitial pH measured by the pH measurement method mentioned below of8.08.

In Comparative Example 1, an oral tobacco material was prepared in thesame manner as in Example 1, except that sodium carbonate and glycerinin amounts corresponding to 2.7% by weight of sodium carbonate and 5.0%by weight of glycerin on the basis of the dry weight of the powderedtobacco were added to the prepared water. The obtained oral tobaccomaterial had a final water content of 26.53% by weight and had aninitial pH measured by the pH measurement method mentioned below of8.11.

Examples 3 and 4 and Comparative Examples 2 and 3

A raw material powdered tobacco was prepared by blending, as rawmaterials, powders of Rustica, dark-cured tobacco and tobacco mid-rib inamounts of 35% by weight, 15% by weight and 50% by weight, respectively,and the water content thereof was measured by the following technique.

The water content of 5.0 g of the raw material powdered tobacco wasmeasured at 80° C. by using a heating and drying type moisture analyzer(MX-50 manufactured by A&D Company, Limited). As the result thereof, thewater content was 12.7% by weight. From the water content of this rawmaterial powdered tobacco, the amount of water required for adjustingthe final water content of the oral tobacco material to approximately15.0% by weight or 25.0% by weight was calculated, and the calculatedamount of water was prepared.

In Example 3, an oral tobacco material was prepared in the same manneras in Example 1, except that sodium carbonate, sodium dihydrogenphosphate and glycerin in amounts corresponding to 5.8% by weight ofsodium carbonate, 4.1% by weight of sodium dihydrogen phosphate and 5.0%by weight of glycerin on the basis of the dry weight of the raw materialpowdered tobacco, respectively, were added to the prepared water thatwas necessary for adjusting the final water content to 25.0% by weight.The thus-obtained oral tobacco material had a final water content of26.9% by weight and had an initial pH measured by the pH measurementmethod mentioned below of 7.73.

In Example 4, an oral tobacco material was prepared in the same manneras in Example 1, except that sodium carbonate, sodium dihydrogenphosphate and glycerin in amounts corresponding to 5.0% by weight ofsodium carbonate, 4.1% by weight of sodium dihydrogen phosphate and 5.0%by weight of glycerin on the basis of the dry weight of the powderedtobacco were added to the prepared water that was necessary foradjusting the final water content to 15.0% by weight. The obtained oraltobacco material had a final water content of 18.6% by weight and had aninitial pH measured by the pH measurement method mentioned below of7.21.

In Comparative Example 2, an oral tobacco material was prepared in thesame manner as in Example 1, except that sodium carbonate and glycerinin amounts corresponding to 3.2% by weight of sodium carbonate and 5.0%by weight of glycerin on the basis of the dry weight of the powderedtobacco were added to the prepared water that was necessary foradjusting the final water content to 25.0% by weight. The obtained oraltobacco material had a final water content of 26.1% by weight and had aninitial pH measured by the pH measurement method mentioned below of 7.7.

In Comparative Example 4, an oral tobacco material was prepared in thesame manner as in Example 1, except that sodium carbonate and glycerinin amounts corresponding to 3.2% by weight of sodium carbonate and 5.0%by weight of glycerin on the basis of the dry weight of the powderedtobacco were added to the prepared water that was necessary foradjusting the final water content to 15.0% by weight. The obtained oraltobacco material had a final water content of 18.1% by weight and had aninitial pH measured by the pH measurement method mentioned below of7.12.

Some information about the oral tobacco materials of the Examples 1 to 4and Comparative Examples 1 to 3 described above are listed in Table 1below.

TABLE 1 pH adjusting agent Sodium Sodium dihydrogen Water carbonatephosphate Glycerin content Oral tobacco (% by (% by (% by (% by materialweight) weight) weight) weight) Initial pH Example 1 4.8 1.9 5 25.448.09 Example 2 8.0 4.1 5 26.39 8.08 Example 3 5.8 4.1 5 26.9 7.73Example 4 5.8 4.1 5 18.6 7.21 Comparative 2.7 0 5 26.53 8.11 Example 1Comparative 3.2 0 5 26.1 7.7 Example 2 Comparative 3.2 0 5 18.1 7.12Example 3

The oral tobacco materials obtained in Examples 1 and 2 and ComparativeExample 1 were each put into a storage pack (Lamizip AL-4 manufacturedby Seisannipponsha, Ltd.; a container having moisture-proof property,gas barrier property and light barrier property), and stored for 6months in an atmosphere at a temperature of 25° C. and a relativehumidity of 60%, and in an atmosphere at a temperature of 35° C. and arelative humidity of 60%. During the storage period, the pH was measuredperiodically by the pH measurement method mentioned below. The resultsare shown in FIGS. 1 and 2. FIG. 1 shows the result of the storage inthe atmosphere at a temperature of 25° C. and a relative humidity of60%, and FIG. 2 shows the result of the storage in the atmosphere at atemperature of 35° C. and a relative humidity of 60%. In FIGS. 1 and 2,the line segment a relates to Example 1, the line segment b relates toExample 2, and the line segment c relates to Comparative Example 1. Asis apparent from the results shown in FIGS. 1 and 2, when the oraltobacco material of Comparative Example 1 was stored for 6 months in theatmosphere at a temperature of 25° C. and a relative humidity of 60%,the pH was decreased by about 0.5, and when it was stored for 6 monthsin the atmosphere at a temperature of 35° C. and a relative humidity of60%, the pH was decreased by about 1.0, whereas in the oral tobaccomaterials of Examples 1 and 2, the pH value was decreased little ineither storage condition.

The oral tobacco materials obtained in Examples 3 and 4 and ComparativeExamples 2 and 3 were each put in the above-mentioned storage pack(Lamizip AL-4 manufactured by Seisannipponsha, Ltd.), and stored for 6months in an atmosphere at a temperature of 25° C. and a relativehumidity of 60%. During the storage period, the pH was measuredperiodically by the pH measurement method mentioned below. The resultsare shown in FIGS. 3 and 4. In FIG. 3, the line segment d relates toExample 3 and the line segment e relates to Comparative Example 2. InFIG. 4, the line segment f relates to Example 4 and the line segment grelates to Comparative Example 3. As is apparent from the results shownin FIGS. 3 and 4, when the oral tobacco material of Comparative Example2 was stored for 6 months in the atmosphere at a temperature of 25° C.and a relative humidity of 60%, the pH was decreased by about 1.2,whereas the pH value was decreased by about 0.6 in the oral tobaccomaterial of Example 3 during the storage under the same condition, andthus it is understood that the decrease in pH during the storage wassuppressed. Furthermore, when the oral tobacco material of ComparativeExample 3 was stored for 6 months in the atmosphere at a temperature of25° C. and a relative humidity of 60%, the pH was decreased by about0.4, whereas the pH value was decreased by about 0.25 in the oraltobacco material of Example 4 during the storage under the samecondition, and thus it is understood that the decrease in pH during thestorage was suppressed.

<Method for Measuring pH>

2.0 g of the oral tobacco material was weighed into a vial, 20 mL ofdistilled water was added thereto, and the mixture was subjected to anextraction treatment by shaking at 200 rpm for 10 minutes. The extractwas stood still for 5 minutes, and the pH of the extract liquid wasmeasured by using a pH meter (IQ240 manufactured by IQ ScientificInstruments, Inc.).

1. An oral tobacco material comprising a powdered tobacco, and a basicsalt of carbonic acid and an acidic salt of phosphoric acid as a pHadjusting agent, wherein the basic salt of carbonic acid and the acidicsalt of phosphoric acid are contained in a total amount of 6% by weightor more of a dry weight of the powdered tobacco and are incorporatedsuch that an initial pH of the oral tobacco material becomes from 7 to8.5, and the oral tobacco material has a water content of 15% by weightor more.
 2. The oral tobacco material according to claim 1, wherein thebasic salt of carbonic acid is selected from the group consisting ofsodium carbonate and potassium carbonate.
 3. The oral tobacco materialaccording to claim 1, wherein the acidic salt of phosphoric acid isselected from the group consisting of sodium dihydrogen phosphate andpotassium dihydrogen phosphate.
 4. The oral tobacco material accordingto claim 1, wherein the oral tobacco material comprises the acidic saltof phosphoric acid in an amount of at least 1% by weight of the dryweight of the powdered tobacco.
 5. The oral tobacco material accordingto claim 1, wherein the oral tobacco material is free from magnesiumcarbonate.